You can get rid of the carapils. Not only does SN not use it, but with extract you won't need the extra body. As a point of reference, here's Dean Larson's classic Christmas Tree ale recipe. About as close as you can get to Cewlebration.

What if I got rid of the carapils and crystal, and added 2 lbs. Caramel 60? And then kept the hops the same except added an ounce of Cascade @ 30 mins. That will get my IBU's almost right on, and will also darken it to 15 SRM.